Abstract: The invention provides AABB-poly(depsipeptide)s (AABB-PDPs), a class of biodegradable polymers composed of ?-amino and ?-hydroxy acids with material properties suitable for biomedical applications. These AABB-PDPs belong to the family of amino acid-based poly(ester amide)s (PEAs), which are characterized by the presence of alternating ester and amide functionalities. Containing four ether groups per basic unit, these polymers degrade rapidly by biotic or abiotic hydrolytic action to release dispersed bioactive agents at a controlled delivery rate, are non-toxic, produce digestible breakdown products, and are easy to fabricate by solution polycondensation.